The present invention describes a new method for the production of certain carbohydrate containing compounds related to glycosaminoglycans and glycoconjugates; namely, Glc.beta.1-4GlcNAc, derivatives thereof and substances derived therefrom. In a further aspect the present invention relates to products produced by the above method as well as uses of the resulting products.
Glycoconjugates contain saccharide chains with from one up to twenty monosaccharide units and in which certain sequences have been shown to have biological activity, for example in the binding of different cells, pathogens, toxins, as well as antibodies or other proteins to cell surfaces, in cancer metastasis, in inflammatory processes, for instance selectin-carbohydrate interactions in the binding of white blood cells to the blood vessel wall, as a modifier of the biological activity and stability of glycoproteins, as immunogenic substances, which have potential in the vaccination against different diseases (See for instance Annual Review of Biochemistry, vol. 58 (1989), pages 309-350, and Current Opinion in Structural Biology, for example review articles in vol. 3 (1993) and references therein).
Structures containing the sequence Gal.beta.1-4GlcNAc, called N-acetyl-lactosamine below, are especially of importance and are found for instance in glycoconjugate oligosaccharides of the lactosamine type. The structure is found in blood group structures, for instance Lewis-x (e.g. Gal.beta.1-4(Fuc.alpha.1-3)GlcNAc), sialylated Lewis-x and 3'-sulfated Lewis-x, and is of importance in e.g. selectin-carbohydrate interactions (as reviewed by J. B. Lowe, in Molecular Glycobiology, pages 163-205, Fukuda and Hindsgaul, Eds., IRL Press at Oxford University Press, Oxford, 1994; see also Curr. Opin. Struct. Biol. vol. 3 (1993)).
Glycosaminoglycans such as heparin and smaller fragments thereof have been shown to have biological activity, for example in the binding of different cells, pathogens, toxins, as well as antibodies or other proteins to cell surfaces, in cancer metastasis, in inflammatory processes (See for instance Annual Review of Biochemistry, vol. 58 (1989), pages 309-350, and Current Opinion in Structural Biology, for example review articles in vol. 3 (1993) and references therein; Science (1995), volume 268, pages 432-435).
Structures containing the disaccharide unit GlcA.beta.1-4GlcN, see structures below, are especially of importance and are found for instance in heparin (see e.g., Curr. Opin. Struct. Biol. vol. 3 (1993); Science (1995), volume 268, pages 432-435).
It is of interest to be able to produce derivatives of GlcA.beta.1-4GlcN in large quantities for biological/clinical studies/tests, for example for inhibition or modification of the selectin-carbohydrate interaction in vivo to inhibit/modify cell-mediated inflammatory processes (for instance in acute septic shock, ARDS, reperfusion injuries, rheumatoid arthritis, virus-induced pneumonia, psoriasis and the like).
Chemical methods known heretofore to produce GlcA.beta.1-4GlcN and derivatives thereof have demanded multi-step synthesis and are often expensive and labor intensive.